Apparatus for controlling pressure



Nov. 15, 1949 R. R. ,MCINTOSH 2,489,090

APPARATUS FOR CONTROLLNG PRESSURE Filed Oct 12 1942 4 Shee'ts-Sheet l I I n o mf E N m A ORNEY NOV. 15, 1949 R R MclNTOSH 2,488,090

APPARATUS FOR CONTROLLING PRESSUREV Filed Oct. 12, 1942 4 Sheets-Sheet 2 5 Roberlltosh BY @CPM A ORNEY Nov. 15, 1949 R, R MCmTOsH 2,488,090

APPARATUS FOR CONTROLLING PRESSURE Filed Oct. l2, 1942 4 SheebS--SlxeefI 3 53K@ B INVENTOR RobertRMclntosh BY 61.0%@

A ORNEYV Nov. 15, 1949 R. R. MCINTOSH 2,483,090

APPARATUS FOR CONTROLLING PRESSURE Filed oct. 12, 1942 4 sheets-sheet 4 INVENTOR Robert R Mclntosh ATTORNEY Patented Nov. 15, `1949 UNITED STATES Ar 2,488,090 APPARATUS FOR CON'IBGLLING PRESSURE Robert R. McIntosh, Battle Creek, Mich.

Application OctoberV 12, 1942', Serial No.461-,665-

16 Claims. l.

The present invention. relates broadly to draft regulation, and in its specific phases it relates more particularly to methods and apparatus for use in connection with the regulation of induced draft pressures in railway locomotive smoke boxes.

Railway locomotives for along period of time have utilized exhaust steam from the driving cylinders for creating induced draft. The creation of that induced draft is accomplished in the locomotive smoke box by directing at least a portion of the exhaust steam from locomotive cylinders out through the locomotive smoke stack to produce a syphonA effect. This syphon effect in turn reduces the pressure inthe smoke box and` produces induced draft whichV is transmitted through the re tubes to the nre box of the locomotive. In order to moderately compress and lower the range of suction pressures created in` this manner, it has been standard practice to install baffles, partition plates, and netting in the smoke box, and to place a long ignition arch in the nre box. The extent to which this procedure can be carried is limited due to its adverse. effect on the lower ranges .of suction pressures. The higher suction pressures produced. in this. man,- ner under normal operating conditions notV only. reduce the combustion efficiency of the locomotive but also interfere with the :uniform burning of the fire bed. The superheater lunits, stay bolt heads, smoke stack, smoke stack extension, and other front end parts which come in contact with the products of combustion which carry an excessive amount of abrasive material', due to the pulsating high velocity flow caused by the conventional induced draft generation, are rapidly worn out by abrasive action. Two ways of improving the drafting of a railway locomotive in.

manner overcoming or at least substantially reducing the prior diiculties in this held. have been set forth in my U. S. Patents No. 2,379,916, granted July l0, 1945, and No. 2,377,895, granted June 12, 1945. These two patents deal with multiple suction pressure level draft regulation.

through the use of a plurality of separate air inlet valves in the smoke box. The operation of those inlet valves is suitably controlled in accordance with predetermined settings based on the drafting demands of the locomotive, or manually if desired. My present invention involvesy the modification, simplicatiomand improvement of the aforementioned inventions wherein the use of multiple dampers are eliminated.

Accordingly among the objects of the present invention is the provision ofi a single damper mechanism which is adapted to control the upper y' suction levelsin the locomotive, smokeboxzat a.. plurality of points which. are prechosen to. meetv the induced draft requirements..

Another object is to provide an apparatus.y for 1 controlling a single. inletL damper in manner` per-.-

mittingsarne to open at different `prescribed suction pressure levels.

Afurther object is to provide a single. draft control damper, which is supplied with a weighting system which addsor removes weight from said; damper in accordance with changes to be made.-

indraft suction pressure levels.

A further object Yis to provideautomatic con',- trol, manual control, orl both typesof control in i connection with the control of. suction pressure levels in a locomotive smoke box by meansofa sing-le damper mechanism. l

A stillv further objectis to provide. a single damper mechanism for regulating locomotive., drafting in manner permitting the. elimination of all or a substantial portion ofthe bafiles, partitions, netting, etc. in the locomotive front. end.

Still further objects and advantages. of. the. present. invention will appear; as. the; description proceeds.

To the accomplishment of the foregoingand re.-

Figure 2 is a partially sectioned, diagrammatic,

elevationaiview taken along line 22. ofFigure` 1, and with manual as well as one formof automatic control mechanism shown in enlarged size and in connected position.

Figure 3 is an elevational View of the cam and valve assembly, on reduced scale, lookingv in theV direction of the arrows along line 3-3 of Fig-v ure 2.

Figure 4 is a top View of the cam assembly look' ing in the direction of the arrows along line 14-4 of Figure 3.

assembly of one form-of valvepartlcularly adapt-Y ed for use as shown in Figures 2 and 3.

Figure 6 is an enlarged and partially sectioned central elevational assembly of a preferred form of the present invention.

Figure 5 is a partially sectioned elevationaly Figure '7 is a plan view as taken along line 'I--1 of Figure 6 looking in the direction of the arrows, but with the dome-like cover removed and certain parts broken away for clarity of illustration.

Figure 8 is a plan view of the weights and weight lifting forks as taken along line 8 8 of Figure 6 looking in the direction of the arrows, but with parts broken away for clarity of illustration.

Figure 9 shows a diagrammatic arrangement for controlling the suction pressure levels of an oil fired locomotive.

Figure 10 shows a diagrammatic arrangement for electrically controlling the suction pressure levels of a locomotive.

Referring more particularly to Figures 1 and 2 of the drawings, the locomotive l has a smoke box 2 with conventional door 3 at its front end for use in inspecting or repairing the various parts mounted within the smoke box or accessible therethrough. An exhaust stand 4 with nozzle 5 is connected in conventional manner to the exhaust outlet from the driving cylinders (not shown). Directly above the exhaust stand is a smoke stack which has a flared bottom which is commonly referred to as a petticoat. The delivery of the exhaust steam from the nozzle of the exhaust stand through and sealing the inside of the smoke stack creates suction in the locomotive smoke box when the locomotive is under motion. The suction pressures thus produced in the smoke box are transmitted through the locomotive fire tubes (not shown) to the re box (not shown) to facilitate combustion of fuel in the latter. A blower ring l, conventionally connected for delivery of live steam up the smoke stack, is utilized for creating a light suction pressure when the locomotive is standing, drifting, or otherwise requires a slight increase in draft.

Mounted in the upper portion of the smoke box between the smoke stack and door 3 is a tubular member 8, which, for simplicity of removal, is preferably flanged at both ends and conventionally joined to flanged end tubular members 3 and l 0 which in turn are welded or otherwise suitably joined in substantially air-tight manner to shell Il of smoke box 2. This smoke box shell is cut away at the outer ends of tubular members 3 and l0 to provide free access of air through these tubular members into tubular member 8. In order to permit ready closing of the inlet ends of tubular members 9 and I6, sliding doors i2 and I3 are provided and these in turn are held in place and guided in their endwise movement by means of ways I-'I and I5. Tubular members 8, 9, and I0 may be of various cross-sectional contours although one of the most simple forms of same involves the use of a fiat top rectangular section. Tube 8 for instance, may have a suitable opening I6 (Figure 6), or the equivalent, in the flat top of same for a purpose to be hereinafter described in detail. The upper face of tubular member 8, at opening I6, may be provided with a ring Il suitably welded or otherwise fastened thereto and faced to form a valve seat. Mounted directly above tubular member 8 is a valve assembly which will now be described in detail.

The closing of opening IG in tubular member 8 is accomplished by means of a valve disc I8 mounted on shaft I9 in conventional manner, for instance by means of collars 20 and 2i, which, if desired, may be welded both to shaft I3 and valve disc I8. The sealing of valve disc I8 on ring Il may be accomplished in various ways, and one of the most convenient involves the use of a gasket 22 formed from a woven strip of asbestos packing which is approximately 1% x 1/4 in section and riveted on or at 2 centers to the under face of disc I8 in the area which lies over valve seat ring I1. The latter may be provided with a groove 23 directly below the rivet circle of the gasket to provide a clearance for same as well as a better seal under operating conditions.

Depending into the upper portion of the locomotive smoke box 2, directly above valve disc I8, is a pan 24. This pan may be joined in substantially air tight manner to the locomotive smoke box by various means, for instance by welding, or the like. A preferred construction involves the use of a flanged ring |33 which is anchored to smoke box shell il by welding, riveting, or the like. The joining of pan 24 to this ring by means of bolts, studs, or cap screws, makes the assembly readily removable for repairs, et cetera. The upper edge of pan 24 is preferably flanged outward to facilitate fastening to ring E03. This flange 25 is also adapted to have mounted thereon a suitable hood member 2t with flange 21 adapted to be joined in conventional manner to flange 25 of pan 24. Where there is ample room ahead of the smoke stack, pan 24 may be made with a circular top. Sometimes, however, attachments to a locomotive front end ahead of the smoke stack limit the available space and in that case pan 24 may be made narrow lengthwise and long crosswise of the locomotive smoke box to fit the available space.

Under operating conditions, it has been found that valve disc I8 tends to spin and thus cause unnecessary wear. This may be avoided by various constructions, and one of the most simple ways of doing so consists of anchoring one or more guide rods 28 on the upper face of valve disc I8 near the outer edge thereof, and providing inverted cups 29 in corresponding location within pan 24. The raising and lowering of valve disc I8, under these conditions, merely causes guide rods 28 to move up and down in cups 29 of pan 24 thus preventing rotation of the valve disc. The guide rods in this case are made a little longer than the actual clearance space between the top of valve disc I8 and the bottom face of pan 24 to insure that rotation will be completely avoided.

Mounted on pan 24 is a carrier plate 30 which may be partially cut away as shown in Figure 6 for purpose of lightening the assembly. A pillow block bearing 3l suitably joined to carrier plate 30 acts to guide the upper end of shaft I9 in its up and down movement. This pillow block bearing may be of either the oilless or greased type. The lower end of shaft I9 is guided by means of a bearing 32 which may be of either the greased or oilless type and which in turn is mounted on a supporting member 33 -which extends across tubular member 8 and is anchored at both ends thereto. Shaft I9 is provided with an enlargement 34 which may be either a unit part of shaft I9, or a collar conventionally fastened thereto, and the showing in Figure 6 is intended to diagrammatically cover these various forms of construction. The bottom of pan 24, at the point where shaft I9 passes therethrough, is provided with an opening 35 of sufcient size for enlargement 34 to freely pass therethrough. A closure member 36 is preferably mounted directly above opening 35, and for convenience this closure member may be of the split and pivoted type commonly used with annular openings,

Valve disc i8 which is exposed on-its upper face to-suction pressures within the smoke box, and at its under face. to atmospheric pressures in. tubular member 8, may be made of such an assembled weight and sizethat when weights 3l and 38 are in elevated position, the exceeding of a predetermined minimum suction. pressure in the smoke box will cause valve disc |8.to move upward from its seat and permit the ingress of air from tubular member 8 into the smoke box to restrict the suction pressure therein substantially to the predetermined mininum. When a predetermined higher suction pressure is to be permitted in the smoke boxi then weight 33 may be lowered to the position shown in Figure 6 so that it rests on enlargement 34 of shaft I9 whereupon the disc valve assembly is increased in weight to the extent of the weight thus added, and the suction pressure necessary to lift same is greater.

If astill higher suction. pressure is to be premitted in the smoke box, then weight 31 may be lowered to the position shown in Figure 6 so that same is added along with weight 38 to that of the assembly including valve disc I8. The use of two i weights with a suitable operating mechanism thus makes possible the controlling of the draft suction pressures in the smoke box substantially at 3 diierent' levels. This invention, it is to be understood, is not limited to the use of two weights rand 3 levels, but rather to one or more weights and two or more levels since such variations do not depart from the spirit of the present invention. For convenience of illustration,

weights 31 and 38 have been shown in lowered position, although underractual operating conditions they may be normally either at upper or lower positions. The mechanism for raising and lowering weights 3l and 38 will now be described.

Mounted on carrier plate 3! are a pair of cylinders 3S and di). Cylinder 39 is conventionally provided with upper and lower headers 4l and 42 which are anged and joined to carrier plate 36 by means of studs 43 which also pass through i a shimming block A14 (Figure '7). Passing through lower header 42 is a piston rod 45, the upper end of which carries piston 46 while the lower end of same is fastened to lower fork member 41. The fork end of this fork member is adapted to pass. under radial flange 48 of weight 38 and clear same slightly when piston is in its lowermost position as shown in Figure 6. In order to make a smoother operating combination, lowerv fork member 4l is counterbalanced by means of a weighted end 49 which substantially balances weight 3S about the center line of piston rod d5. As a means of guiding fork member i1 at all times, weight member 49 is preferably provided with substantially nat sides 50 and 5l, which in actual operation, slide up and down guide ribs 52 and 53 which are conventionally joined to pan 24. Y

In similar manner, cylinder 40 is provided with upper and lower headers 54 and 55, which are fastened by means oi studs 5B, and shimming block 5l to carrier plate 30. Piston rod 58 extends through lower header 55 and has piston 59 mounted on its upper end. The lower end of piston rod 58 is fastenedto upper fork member d. The fork end of this fork member is adapted to engage the underiace of radial ange 6l onA upper weight 31 for. raising and lowering same. The fork end of upper-fork Gilin this case, along with Weight 3l, is made radially larger so that lower fork 41 and weight 38 can. pass upward without interfering with theV fork end of upper fork 6G even though same remains inits lowermost position. In order to balance the upper fork 56 when it is lifting. weight. 31, the counter weighted end 62 of this fork is preferably provided with substantially flat sides 63 and t4 which, in actual operation, slide up and down guide ribs @5 and Se conventionally joined to pan 2.4.

Where a fluid pressure system isY utilized ior the raising andlowering of weights 3l and 38, the lower ends of cylinders 'se andii may be connected to a suitable source of low pressure gaseous fluidr such asair or steam, such. pressure being sufficient to normally hold pistons it and` 5d in their uppermost positions lwith weights3'l and e8 elevated.v Then when it is desiredto lower. one of the weights, for instanceweight 38, it is only necessary to deliver a suitable higher pres sure gaseous fluid to the upper end of cylinder 33 to drive piston 5; to its lowermost position. This will cause weight "it to rest on enlargement 35i of shaft le and thus increase the weight of the valve assembly so that the suction pressure in the smoke box will have. to raise to a higher level before disc valve I8 will raise to permit air to iiow from tubuiar member 8 into smoke box 2. The apparatus will then substantially hold that suction pressure as the maximum over a considerable range of operation within the capacity of the valve. If it is desired to further increase this suction pressure, then a gaseous fluid at suitable pressure may be delivered to the upper end oi cylinder i3 to force piston 5S. to its lowermost position, whereupon weights'i will be added to the valve assembly weight including weight 33.` The elevating of` the valve disc assembly under these conditions merely carries Weights 3l and 38 in an up and down path. while fork members l? and t@ remain in xed lowermost position..

Various ways of operating the present suction pressure controlling apparatus may be utilized without varying from the principles of the present invention. For instance, it may be decided to controlthe suction pressure level inaccordance with the rate of iuel feed, or in accordance with the percentage of cutoi, or manually, or even. by combinations of these or other prechosen controlfactors. For simplicity of understanding the operation of the invention, same will now be described in terms of automatic control in step with prescribed variations of cutoff settings. For purposes of description, but without being limited thereto, let us assume that three suction pressure levels in the smoke box are desired and that these are respectively 5%", 5%, and 4% oi water. Under these conditions, with weights 3l and 313 held in elevatedr position to permit free up and down movement of the assembly including disc valve IS, the weight ofthe latter may be so proportioned that it will start to elevate and. admitl atmospheric air into the smoke box when the suction pressure therein reaches and starts to exceed-14%." of water'. Weight 38, in thatl case, will be made of such a size that when lowered Y and left resting on enlargement 3d ofv shaft I9,

it will increase the total weight of the valve assembly to a point where same will start to open at a suction pressure ofk 51,45 of'water. The lowering'of a suitable size weight 3l, and the addition of same to the combined weight ofthe valve disc assembly plus weight 38 should prevent the valve assembly from opening until a suction pressure of 5%" of water has been reached in the smoke box. Under these conditions, the liftingv of weight 31 by means of fork 68 and the associated mechanism will automatically return the suction pressure level to the intermediate one, and then upon lifting weight 38, that in turn will automatically return the suction pressure level to the lowest one. It is thus obvious that all that is necessary to the functioning of the system is the raising and lowering of weights 31 and 38 in accordance with draft level change requirements.

The controlling of the raising and lowering of weights 31 and 38 to vary the maximum suction pressure in the smoke box between prescribed low, intermediate, and high suction pressure levels, through the actuation of the cut-01T mechanism, may be accomplished in various ways, and one of the most convenient will now be described. The reverse arm 61 of the locomotive has a link 68 (Figure 3) which is suitably connected to the valve gear which actuates the main steam valve (not shown) of one of the driving cylinders so as to control the cut-olf of steam admitted thereinto. Reverse arm 81 is mounted on and keyed to a cross shaft 69, and on the other end of this cross shaft is mounted and keyed to another reverse arm (not shown) for operating a like cutolf control of the main steam valve for the driving cylinder on the opposite side of the locomotive. The operation of reverse arm 81 mounted on shaft 69 is therefore in accordance with the movement of the cut-off setting controls in the locomotive cab (not shown). The increasing of the per cent cut-off under forward travel of the locomotive results in reverse arm S1 being moved in clockwise direction as viewed in Figure 3. To

take advantage of this for controlling the air inlet assembly, a plate 18 with arcuate flange 1| may be anchored to the side of reverse arm 61 in conventional manner, for instance, by means of screws 12. Under these conditions, the arc of flange 1| is set so that its center is approximately on the center line of cross shaft 69. Flange 1| is provided with slots 13 (Figure 4) through which extend studs or cap screws 14 which in turn are fastened to cam shoe members 15 and 13. Assembling the cam shoes on arcuate flange 1| in this manner permits adjustment of the shoes to contact and operate valves 11 and 18 at various cut-off settings, and hence govern the points of shifting of the suction pressure levels in the smoke box.

Mounted on the frame 19 (Figure 3) of the locomotive is an anchor bracket |2| on which are mounted valves 11 and 18. Rollers 88 and 8| of these two valves are adapted to engage cam shoe members 15 and 16. For instance, cam shoe 15 may be adjusted to engage and depress roller 88 of valve 11 at a cut-off setting of thirty per cent. This engagement will connect the high pressure main air line 82 through valve 11 to air line 83 which connects with the top of cylinder 39. The flow of high pressure air then forces piston 46 in cylinder 39 to its lowermost position which in turn deposits weight 38 in contact with the upper face of enlargement 34 on shaft I9. This predetermined amount of weight added to the weight of the valve assembly automatically shifts the suction pressure level at which the apparatus operates from 4% to 51A," of water. Cam shoe member 16, for instance, in turn may be adjusted so as to engage and depress roller 8| of Valve 18 at a cut-off setting of forty per cent so that under those conditions, main air line 82 will be connected through valve 18 and air line 84 to the upper end of cylinder 40. The iiow of high Pressure air in this circuit will in turn force piston 59 to its lowermost position and deposit weight 31 on the top of weight 38 which is resting on the upper face of enlargement 34 of shaft I9. This predetermined amount o f weight added to the weight of the valve assembly automatically shifts the suction pressure level control from 5%." to 5% of water. In other words, when weights 31 and 38 are in their uppermost position, the apparatus will restrict the maximum suction pressure to the lowermost pressure level up to a cut-off setting of thirty per cent at which point weight 38 is lowered to raise the maximum suction pressure level to the intermediate one. Then as the cut-off is further increased, the assembly maintains this intermediate suction pressure until the cut-off setting reaches forty per cent, at which time weight 31 is lowered to raise the maximum suction pressure level to the highest one which is to be maintained. This pressure is maintained until the cut-oil setting again drops below forty per cent, a thing which through the operation of valve 18 automatically reduces the suction pressure to the intermediate level which is maintained until the cut-olf setting is either again raised above the forty per cent or lowered below thirty per cent, the latter, through the operation of valve 11, resulting in a shift to the lowei` suction pressure level once more. It is to be understood that the speciilc cut-off percentages noted are used as illustrative of the operation of this apparatus, and are not to be considered as a limitation on the invention since obviously other cut-off settings may be used so long as the principles herein set forth are utilized.

Where the gaseous fluid which is used for moving pistons 46 and 59 in cylinders 39 and 40 respectively is in the form of air, the main air line 82 which, for instance, may carry air at approximately one hundred and ten pounds per square inch, is connected through pressure reducer 85 to low pressure lines 86 and 81, the former of which leads to the lower end of cylinder 49. Low pressure air line 81 connects pressure reducing valve 85 to the lower end of cylinder 39. When either piston 46 or 59 is moved downward, due to the supply of high pressure air to the upper end of cylinders 39 and 4U respectively, this causes a back flow and building up of low pressure air in lines 86 and 81. In order to relieve this back pressure, a pressure relief valve 88 is provided. Where air pressure reducing valve 85 is set to deliver air at thirty pounds per square inch gauge, the pressure relief valve 88 may be set to relieve air in lines 86 and 81 when the pressure therein reaches or tends to exceed a prechosen pressure, for instance thirty-five pounds per square inch gauge. This moderately higher setting of the pressure relief valve outlet pressure as contrasted with the pressure reducing valve outlet pressure causes the trapped air to cushion the return movement of pistons 46 and 59 to the upper end of their respective cylinders.

Valves 11 and 18 are preferably identical in construction, and for simplicity of understanding same, one of these valves, namely valve 18, has been shown diagrammatically in partial center section in Figure 5. Referring more particularly to that gure, the movement of arcuate cam 16 (Figure 2) into contact with and over roller 8| will move push rod 99 downward under the cushioning influence of spring 9| carried by depressor arm 89 pivotally mounted on supporting member 99 by means of pivot pin |80. This downward movement in turn will depress spring pro- Ylaesepeo iected ball bearing 92 and allow fluid to flow under pressure from compartment 93 into cavity k91| and hence out through pipe 84 to the upper end ball v92. At the same time check valve 95 Vmoves upward to the position shown in Figure 5, and this allows fluid in air line 84 to flow backward into compartment 94 and thence through compartment S6 and a small vent opening 91 to the atmosphere to permit release of the piston rod assembly which has been held with the piston at Vlowermost position due to the air pressure Idelivered through air line 85;. Vent opening 91 vand the connections leading thereto may be made relatively small, if desired, so that they will not seriously interfere with the simultaneous operation of the suction pressure level control either manually, or other than by the cam operated system just described. The placing of a valve 98 (Figure 2) which may be of conventional type, such as `a needle valve, gate valve, globe valve, or the like, in the main air pressure line 82 ahead of cam operated valves 11 Aand 18 `will make possible the shutting off of air to valves 11 and 18, and the completely independent operation of the pressure level control cylinders by manual control, or other extraneous control means.

The pressure levels may be manually controlled ure 6) will be lowered into contact with enlargei ment 34 thus Ashifting the upper pressure level to -be maintained in the smoke box from the lower level to the intermediate level. Then by opening valve |02 (Figure 2) high pressure vair will be delivered from main air line 82 to the top of cylinder 4B which in turn will lower weight 31 (Figure 6) into contact with the upper face of weight 33 and thus Vraise the upper suction pressure level to be maintained in the smoke box to the high level. The return -of the systemto intermediate and then low pressure levels is accomplished by first closing valve |02 and then valve mi. VIt is perfectly possible to vcontrol the Aapparatus manually with valve B8 either open or closed, although the latter would prevent the cam operated system from operating in conjunction with the manualcontrol. The supplemental use of manual control presents the advantage of giving the locomotive engineer or `fireman an opportunity to raise the suction vpressure level manually from low or intermediate to a high level if the suction pressure for some reason is not quite high enough and the cut-oil setting not sufficiently advanced to shift the suction pressure under operating conditions to the desired higher level.

The air piping and control system for normally holding weights 31 and 38 in uppermost position and the lowering of same'by means of Athe application Yof suitably high pressure above pistons d and 59 of cylinders 39 and 4B has already been described. 'Ihe invention, however, is not limited to that procedure, and an alternative procedure will now be described in connection with the controlling of an oil fired locomotive. Referring i l0 more particularly to Figure 9, high pressure ai-r line 82 is connected through pressure reducing valve 85 to the upper end of cylinders 39'and 4lll! by means of pipes 81 and 86 respectively. The application of this pressure will normally force piston rods le and 53 downward and hold them down so that weights 38 and 31 (Figure 8) will be in their lowerniost position when valves |04 and H55 are closed. vThe fuel oil supply line it would be connected by means of valve it? to feed pipe il for delivery of oil to burner |09 in the loco- `moti-ve nre box (not shown). The operation of valve iiil ma;T be controlled in conventional manner by means of an operating lever llll. This operating lever, for instance, might be provided with an extension pivotally connected to an :operating link l E2 which in turn would' be pivot- -ally connected to valves Illl and M35 by means of operating arms lf3 and H4. When the fuel oil being delivered to burner |09 is of relatively small .quantity flew, valves mil and HB5 would be open vand as a result weights 31 and 38 would be held in their uppermost position. Under these conditions `when the fuel feed is increased to a prescribed point by the manipulation of operating lever llt, the movement of link H2 will automatically move operating arm H3 to a point where valve lili is closed. This Yautomatically permits piston rod lle to move downward and .deposit weight 38 on enlargement 34 of shaft i9, thus increasing the weight of the valve assembly iand transferring the upper limits of the suction pressure in the smoke box to the intermediate level. A still further increase in fuel feed due -to the movement of operating lever lill would, at a prechosen point, close valve through the Jactuation of operating arm Ill. This in turn would llower weight 31 onto the top of weight 38 and thus increase the maximum suction pressure in the smoke box to the upper level. Reverse movement of operating lever l l@ would first open valve W5 to elevate weight 31, and then open valve |04 to elevate weight 38, thus progressively shifting the suction pressure levels in the smoke :box from high to intermediate and then to low. Connecting cylinders 39 and 4|! in this manner presen-ts the advantage of dropping weights 31 and 38 whenever anything goes wrong with the air pressure system. The dropping of these weights automatically increases the induced draft suction pressure level, a thing which would be important since it would permit maximum -draft for the locomotive and take care of peak operating conditions even though the air system for .operating valves 39 and d@ was out of order. v'Pressure relief valve 8S set at a somewhat higher pressure than pressure reducing valve 85 would preferably -be used as before described. Valves .lit and m5 in preferred construction would be provided with a bleeding outlet o-n the cylinder side of same so that when these valves are closed,

the air pressure in the corresponding pipes .83 and 8d-would be gradually relieved to permit the ready functioning of the system.

The operation of the system through the agency of air or steam pressure provides feasible means Aof control of the damper system due to the presence of steam and compressed air on the locomotive. The invention, however is notlimited to that type of control, since the latter may beof electrical nature. Referring, for instance, 4to Figure l0, the system may be electrically connected to a suitable source of electric power. Thissystem utilizes solenoids 39a and 40a electrically connected lto the main line through rcani l'actuated switches I I5 and I I6. Rods 45a and 58a in this case would not only carry fork members vand B0, as well as weights 38 and 31, in elevated position under normal operating conditions with no electricity supplied to solenoids 39a and 40a. Cam shoes 15 and 16 mounted on arcuate flange 1I would, in this case be arranged so that switch I I5 would close first and deliver electricity through solenoid 39a which would be so-connected in the system as to force rod 45a substantially to its lowermost position against the resistance of spring II1. This operation of solenoid 39a would automatically lower weight 3B onto enlargement 34 of shaft I9 and due to this added Weight, it would move the upper suction pressure level from low to intermediate. Still further movement of reverse arm 61 to increase the cut-olf would actuate switch IIB at a prescribed point, and this in turn would electrically .force rod 58a. and weight 31 downward until the latter rests on weight 38, thus raising the upper suction pressure level in the smoke box from intermediate to high. Moving reverse arm 51 in the opposite direction would, at the prescribed settings, automatically actuate switches IIB and II5 to reverse the process just described and return the system from high to intermidate and then to low upper suction pressure level. The actual setting of cam shoes and 16 under these conditions would be in accordance with cut-off settings which have been prechosen to vary the suction pressures as has been described in detail above. Manually operated electrical switches II9 and |20 may be mounted in the locomotive cab (not shown), or at any other convenient point on the locomotive, and the actuation of solenoids 39a and 40a directly controlled through the operation of same. Switches IIS and thus provide for manual control of the system,

While switches I I5 and IIB provide for automatic control of the system at predetermined points through the cut-01T settings of the locomotive gear. The operation of the system in this manner has been described by way of illustration of the principles involved, and same is not to be -considered as a limitation on the scope of the invention.

The electrical system shown in Figure 10, and

described in detail above, is adapted for varied operation. For instance, springs H1 and II8 may be omitted, and this in turn will allow rods 45a and 58a to normally extend down with fork members 41 and 60 (Figure 6) in lowermost position and weights 38 and 31 resting on collar 34 of shaft I9. Cam shoes 15 and 15 in this case would be adjusted to close the electrical circuits through switches II5 and IIB when predetermined upper suction pressure levels below the vmaximum are to be maintained. For example if the suction pressure is to be held from exceeding a predetermined low suction pressure when the cut oii" is below then at all cut-oif settings below 30% switches IIE and IIB would be held closed by cam shoes 15 and 15 respectively. The electrical circuits in this case would be connected so that the solenoids 39a and 40a would exert a lifting force to elevate forks 41 and 60 with weights 38 and 31 whenever switches II5 and IIB were closed. If on the other hand the suction pressure is to be held from exceeding a predetermined intermediate suction pressure when the cut-off setting is between 30% and 40%, then cam shoes 15 and 15 would be so adjusted that only switch H6 would lbe closed in this range. The closing of switch IIS would cause weight 31 (Figure 6) to be elevated while weight 38 would be left in lowermost position where it would increase the valve and valve shaft assembly weight as previously described. Connecting the electrical system in this manner presents the advantage that in case the supply of electricity fails, the upper suction pressure level will be continuously effective so as to take care of maximum combustion requirements at all times.

While the description of the present invention has set same forth in the examples in terms of using two or three suction pressure levels, it is to be understood that the invention is not limited to that but rather the principle involved is the lcontrolling of the suction pressure at two or control the upper suction pressure to be main-A tained at any time in accordance with the prechosen pressure level requirements as varied by the mechanism for controlling the shifting of same.

Other modes of app-lying the principle of my invention may be employed instead of those explained, change being made as regards the means herein disclosed, provided those stated by any of the following claims or their equivalent be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a pressure reducing apparatus, the combination of a hollow member, an inlet means having a substantially horizontal opening into said hollow member, a valve for said opening, said valve being mounted toy control fluid flow from said inlet means into said hollow member, means for controlling the movement of said valve in a substantially vertical direction to and from the upper side of said opening, loading means for said valve, and means for adding and removing said loading means from said valve.

2. In a pressure reducing apparatus, the combination of a hollow member, an inlet means having a substantially horizontal opening into said hollow member, a valve for said opening, said valve being mounted to lcontrol iluid flow from said inlet means into said hollow member, means for controlling the movement of said valve in a substantially vertical direction to and from the upper side of said opening, a plurality of weights, and means for engaging said weights for the lowering and lifting of same to and from the upper side of said valve.

3. In a pressure reducing apparatus, the combination of a hollow member, an inlet means having a substantially horizontal opening into said hollow member, a valve for said opening, said valve being mounted to control fluid flow from said inlet means into said hollow member, means for controlling the movement of said valve in a substantially vertical direction to and from the upper side of said opening, a plurality of weights, means for engaging said weights for the lowering and lifting of same to and from the upper side of said valve, and means for controlling the operation of said weight lifting means.

escaneo 4. In .a pressure Ycontrolling apparatus, the 4combination .of a compartment wherein pressure is to be controlled, an inlet means with lupper face, said inlet means having -a substantially horizontal opening in .its upper face, -a valve for :said opening, means for guiding said valve in a .substantially vertical direction to and from the upper side of said opening, .a -pluralityof weights, `a plurality .of means ier :individually engaging .said weights for the raising and loweringof same, separate means -for operating said vindividual weight engaging means, and means for controlling `the operation of said individual weight engaging means.

:5. In a pressure controlling apparatus, the combination of a compartment wherein pressure is to be controlled, an inlet means with upper face, said inlet means having a substantially horizontal opening in its upper face, a valve for .said opening, means for guiding said valve in a substantially vertical direction to and from the Supperside of .said opening, a plurality of weights, ;a plurality .of means for individually engaging :said weights for the raising and lowering .of same, separate means for operating said individual weight engaging means, and cam including means .for controlling 'the operation of said individual 4weight vengaging means.

6. In a ,pressure controlling apparatus, I.the combination of -a v'compartment Vwherein vpressure is to :be controlled, yan inlet means with upper face, .said inlet means having .a substantially horizontal opening in its upper face, a valve for said opening, means `for guiding said valve in a VVSubstantially 'vertical direction to and from the i upper side of :said opening, `a plurality of weights, Va plurality of means for individually engaging said weights for the raising and lowering of same,

.separate means for operating vsaid individual weight engaging means, and at least manual means for controlling the operation of said individual weight engaging means.

7. In a pressure controlling apparatus, the .combination of a compartment wherein pressure is to be controlled, :an inlet means with upper face, said inlet means having a substantially horizontal opening in its upper face, a valve for said opening, means for guiding said valve in a .substantially vertical `direction to .and from .the

upper side of said opening, a phufalityniweights, a plurality .of means for individually engaging said weights 'for the raising and 'lowering of same, separate means :for voperating said :individual Vweight .engaging means, and electrically .operated means for Acontrolling vthe-move- 3 ment of said individual weight engaging means.

.8. In a pressure controlling apparatus, Vthe combination .cia .compartment wherein pressure is to 1be.controlled,.a .tubular inlet member, said Vinlet member .having .an .upwardly directed open- .ing into Ysaid compartment, a ydisc valve for said opening, means for carrying said valve to and from said opening for respectively sealing and opening same, a plurality of separate weights, a fork means for each of said weights, means for moving said fork means to and from said valve, whereby same may be used to add and remove one or more of said weights from said disc valve, and means for controlling the movement of said fork means.

9. In a pressure controlling apparatus for a locomotive smoke box, the combination of means for creating suction press-ure in said smoke box in excess of the maximum required, a tubular inlet member, said inlet member having an up- 14 "wardly directed opening into .said .smoke box, a disc valve for opening and closing said opening, a .shaft .on which said disc valve .is radially mounted, "means yfor guiding said vshaft in endwise direction in manner such that said `disc valve will be movable .to and from said opening lor respectively. sealing ,and opening same, a plu rality :of separate weights, .a fork .means for each of said weights, .means for moving said ifork means .to and vfrom said valve whereby same may be used to add or remove one or more of said weights from said valve and shaft assembly, a shaft means lon which said forks are mounted for separate movement, a counterweight foreach of .said forks, guide means for said counterweighted torks, a cylinder for each of said shaft and fork assemblies, a piston in each of said cylinders, each roi said .pistons Ibeing mounted on the upper .end oi .said fork .carrying shafts, .fluid conduits connected .to the opposite ends of each of ysaid cylinders, and means ior controlling the supply of fluid under pressure to `said cyiinders, whereby said pistons .will be .moved therein .and weights added to or removed from the valve .and `shaft .assembly in accordance with prescribed Variations in the maximum suction pressure to be .permitted in-said smoke box.

'10. In sa pressure controlling apparatus for a locomotive smoke box, the .combinationoi' :means for creating suction pressure in said smoke .box in excessof the maximum required, .a tubular inlet member, said inlet member having an `upwardly directed opening into said smoke box, a disc valve for .opening and closing said opening, `a shaft .on which said .disc valve is radially mounted, means `for guiding said shaft in endwise .direction in manner such that said disc valve will be movable to and from said opening for respectively sealing and opening same, a plurality of .separate weights, a fork means for each of said weights, means for moving said fork means to and 'from said valve, whereby same maybe used .to add `or remove one or more Aof said weights from said valve and shaft assembly, shaft means on which said forks are mounted for separate movement, a counterweight for each of said vforks, guide means for said counterweighted the maximum suction pressure `to be permitted in said smoke box.

l1. In a pressure regulating apparatus, the

veombinatiz-)n vof an inlet means with `opening therein, an endwise movable valve assembly for said opening, means for axially guiding the valve of said valve assembly positively to and from said opening, at least one valve loading weight, means for physically adding and removing said weight to accomplish self loading and self unloading of said valve assembly in manner producing at least two operating inlet pressure levels at which said valve assembly will open, and means for controlling the loading and unloading of said valve assembly in accordance with prech-osen conditions.

12. In a pressure regulating apparatus, the combination of a hollow member, an inlet means having a substantially horizontal opening into f' 15 said hollow member, a valve: assembly for said opening, said valve assembly being mounted to control luid flow from said inlet means into said hollow member, means for axially guiding the valve of said valve assembly positively tc and from said opening, and self loading means for mechanically adding and removing at least two load members separately from said valve assembly in manner self controlling at multiple operating levels the pressure necessary to open said valve assembly.

13. An apparatus for controlling suction pressure in a compartment, which comprises an inlet with a valve assembly adjustable so as to open and admit into said compartment through said inlet a controlled amount of suction reducing gaseous fluid when the suction pressure therein reaches a predetermined level, means for mechanically loading said adjus-ted valve assembly so as to increase the suction pressure level at which said valve assembly will open to admit a controlled amount of gaseous iluid through said inlet into said compartment, means for additionally loading said valve assembly mechanically so as to raise its opening suction pressure level still higher, said loading means being also adapted for mechanically removing said loading when the suction pressure at which the valve assembly opens is to be returned to a lower level, and means for controlling the actuation of said loading means so as to operably load and unload said valve assembly.

14. An apparatus for controlling suction pressure in a compartment, which comprises means for creating a suction pressure in said compartment, said suction pressure being adapted to rise above the maximum desired unless controlled, an inlet with a valve assembly adjustable so as to open and admit into said compartment through said inlet a controlled amount of suction reducing gaseous uid when the suction pressure therein reaches a predetermined level, means for mechanically loading said adjusted valve assembly so as to increase the suction pressure level at which said valve assembly will 'open to admit a controlled amount of gaseous fluid through said inlet into said compartment, means for additionally loading said valve assembly mechanically so as to raise its opening suction pressure level still higher, said loading means being also adapted for mechanically removing said loading when the suction pressure' at which the valve assembly opens is to be returned tc a lower level, and means for controlling the actuation of said loading means so as to operably load and unload said valve assembly.

15. An apparatus for controlling suction pressure in a compartment, which comprises an inlet with a valve assembly adjustable so as to open and admit into said compartment through said inlet a controlled amount of suction reducing gasecus iluid when the suction pressure therein reaches a predetermined level, means for mechanically loading said adjusted valve assembly so as to increase the suction pressure level at which said valve assembly will open to admit a controlled amount of gaseous fluid through said inlet into said compartment, means for additionally loading said valve assembly mechanically so as to raise its opening s-uction pressure level still higher, said loading means also being adapted for mechanically removing said last applied load and then the rst applied load t0 return the suction pressure successively in steps to the initial suction pressure level, and means for controlling the actuation of said loading means to both load and unload the valve assembly in operable sequence.

16. An apparatus for controlling suction pressure in a compartment, which comprises means for creating a suction pressure in said compartment, said suction pressure being adapted to rise above the maximum desired unless controlled, an inlet with a valve assembly adjustable so as to open and admit into said compartment through said inlet a controlled amount of suction reducing gaseous fluid when the suction pressure therein reaches a predetermined level, means for mechanically loading said adjusted valve assembly so as to increase the suction pressure level at which said valve assembly will open to admit a controlled amount of gaseous fluid through said inlet into said compartment, means for additionally loading said Valve assembly mechanically so as to raise its opening suction pressure level still higher, said loading means also being adapted for mechanically removing said last applied load and then the first applied load to return the suction pressure successively in steps to the initial suction pressure level, and means for controlling the actuation of said loading means to both load and unload the valve assembly in operable sequence, whereby the maximum suction pressure in said compartment may be controlled within the capacity of the apparatus at any one of three different pressure levels.

ROBERT R, MCINTOSH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 984,550 Fowler Feb. 21, 1911 1,186,303 Frost June 6, 1916 1,615,588 Korngiebel Jan. 25, 1927 1,710,695 Firestone Apr. 30, 1929 2,135,130 Vidalie Nov. 1, 1938 2,147,288 Colihan Aug. 16, 1938 2,241,347 Hem May 6, 1941 2,253,290 Field Aug. 19, 1941 

